1. Field of the Invention
The present invention relates generally to air handling systems, in particular to a fan system for mounting in an object, and more particularly to such a fan system for mounting in a vehicle visor.
2. Description of the Related Art
A wide variety of air handling devices has previously been proposed for conveying and distributing air for various purposes. Such purposes include heating, cooling, ventilating and drying of various objects and spaces. For example, forced air heating, ventilating and cooling (HVAC) systems are commonly used for environmental control in habitable structures for maintaining appropriate temperature and humidity levels for the comfort of the inhabitants.
Another area which involves air circulation for environmental control is in the vehicle field wherein forced air is commonly used for heating vehicle interiors. Heated air is also commonly used for clearing vehicle windshields and windows of condensation on the interior and ice on the exterior. Such condensation commonly occurs when a vehicle windshield or window is at a lower temperature than the vehicle interior, particularly if the air enclosed in the vehicle interior is relatively humid. Such defrosting systems can be used for evaporating condensation on the interior surface of a vehicle window or windshield, and for raising the temperature thereof to melt ice and/or snow on a vehicle window or windshield exterior surface.
Vehicles with water-cooled engines commonly have heater/defroster systems with heat exchangers and fans for circulating heated air to desired locations in the vehicle interiors.
Vehicles equipped with air-cooled engines, however, typically lack liquid engine coolant which can be circulated to a heat exchanger in a fan-driven air stream. Therefore, heat is sometimes drawn off of the relatively hot exhaust manifolds of air cooled engines for heating and defrosting purposes. For example, the engine cooling fan can be utilized for directly an air stream over a heat exchanger connected to an exhaust manifold, which air stream is then conveyed into the vehicle interior. However, such systems are often dependent upon engine speed and limited in effectiveness thereby. Furthermore, conveyance of an air stream from the engine compartment to the vehicle interior can be somewhat inefficient, with substantial heat losses occurring in route.
As an example of such a system, the Handley U.S. Pat. No. 1,586,428 discloses an attachment for automobiles which communicates air heated by a vehicle exhaust manifold to an apparatus mounted o the vehicle windshield for clearing same.
As another example of such a system, the Schackford U.S. Pat. No. 2,064,498 discloses a sleet and mist eliminating device for windshields which includes a fan mounted in a casing secured to a windshield frame portion.
Heretofore there has not been available a fan system with the advantages and features of the present invention, which addresses some or all of the aforementioned considerations.